How Maternal RSV Vaccination and Infant Immunization Are Protecting Babies in the 2025–2026 Season

The short version

Respiratory syncytial virus (RSV) is still one of the top reasons babies in the United States are hospitalized each fall and winter. But in the 2025–2026 season, two prevention tools are working together to reduce severe illness: vaccination during pregnancy and a long-acting antibody shot for infants.

Federal health agencies including the Centers for Disease Control and Prevention (CDC) now recommend:

A single RSV vaccine dose for pregnant people between 32 and 36 weeks of pregnancy during RSV season.
A long-acting monoclonal antibody, nirsevimab, for most infants entering their first RSV season if they are not protected through maternal vaccination.

Together, these approaches are helping lower the risk of hospitalization and serious breathing complications in the youngest babies—those at highest risk.

Why RSV matters for babies

RSV is a common respiratory virus. In older children and adults, it usually causes cold-like symptoms. In infants—especially those under 6 months—it can lead to bronchiolitis (inflammation of the small airways) and pneumonia.

According to the CDC, RSV has historically caused tens of thousands of hospitalizations each year among U.S. children younger than 5, with the highest rates in infants under 6 months of age. Premature infants, babies with heart or lung conditions, and those with weakened immune systems face higher risk of severe disease.

For families, RSV season typically runs from fall through early spring, though timing can vary by region.

How maternal RSV vaccination works

The maternal RSV vaccine, approved by the U.S. Food and Drug Administration (FDA) in 2023 and recommended by the CDC and the American College of Obstetricians and Gynecologists (ACOG), is given during late pregnancy.

Here’s the key idea: when a pregnant person receives the vaccine at 32–36 weeks, their immune system produces antibodies against RSV. Those antibodies cross the placenta and help protect the baby during the first months of life.

In clinical trials published in peer-reviewed journals, maternal vaccination significantly reduced the risk of severe RSV-related lower respiratory tract disease in infants during their first six months. As with most vaccine trials, participants were followed for a defined period, so longer-term protection beyond early infancy is still being studied.

For families, this means protection begins at birth—before a baby is old enough to receive many routine childhood vaccines.

Who should consider it?

CDC guidance recommends one dose of the maternal RSV vaccine during 32–36 weeks of pregnancy if the baby will be born during or just before RSV season. It is not typically given outside this window because the goal is to maximize antibody transfer close to delivery.

As with any vaccine in pregnancy, individuals should discuss timing, medical history, and other vaccines (such as Tdap and flu) with their obstetric clinician.

How infant immunization with nirsevimab works

Nirsevimab is not a traditional vaccine. It is a long-acting monoclonal antibody—essentially a laboratory-made antibody that directly provides protection.

Instead of prompting a baby’s immune system to make antibodies, nirsevimab supplies them. One injection before or during RSV season can provide protection for about five months, covering a typical season.

The CDC recommends nirsevimab for:

Infants younger than 8 months entering their first RSV season, if they were not protected through maternal vaccination.
Certain high-risk children 8–19 months old entering their second RSV season.

Large randomized clinical trials showed that nirsevimab reduced medically attended RSV lower respiratory tract infections and hospitalizations in infants. As with all studies, results reflect the populations studied, and ongoing real-world data continue to monitor effectiveness across different regions and seasons.

How the two strategies work together in 2025–2026

In earlier seasons, some areas experienced supply constraints for infant monoclonal antibodies. Federal agencies and manufacturers have since worked to improve distribution ahead of the 2025–2026 season.

The current U.S. strategy is designed so that most babies receive protection in one of two ways:

Through maternal vaccination (passive antibodies transferred before birth), or
Through nirsevimab after birth, if maternal vaccination was not given or occurred outside the recommended window.

In most cases, babies do not need both. Pediatricians review maternal vaccination history at birth or first visits to determine whether nirsevimab is indicated.

This coordinated approach reflects guidance from the CDC’s Advisory Committee on Immunization Practices (ACIP) and pediatric specialty groups such as the American Academy of Pediatrics (AAP).

What families may be noticing this season

Public health officials have reported shifts in RSV patterns since the COVID-19 pandemic, including earlier or atypical peaks in some regions. With broader use of maternal vaccination and infant immunization, pediatric clinicians are closely tracking:

Rates of RSV-related hospitalizations.
Emergency department visits for bronchiolitis.
Regional differences in timing and severity.

While it is still early in the 2025–2026 season, early surveillance reports from CDC systems suggest that infants who receive recommended protection are less likely to develop severe RSV requiring hospitalization. Final season-wide data will be analyzed after the season concludes.

Symptoms parents should still watch for

Even with protection, RSV infections can still occur. No preventive tool eliminates risk entirely.

Seek medical care promptly if a baby has:

Fast or labored breathing.
Chest retractions (skin pulling in between ribs).
Difficulty feeding or signs of dehydration.
Blue or gray coloring of lips or fingernails.
Unusual sleepiness or difficulty waking.

Most RSV infections are mild, but infants—especially those under 3 months—can worsen quickly.

Access and insurance coverage in the United States

Under federal vaccine coverage rules, most private insurance plans must cover CDC-recommended vaccines without cost-sharing. Medicaid and the Vaccines for Children (VFC) program also cover recommended immunizations for eligible children.

Maternal RSV vaccination is typically covered when administered during pregnancy as recommended. Nirsevimab coverage may be billed under a child’s medical benefit rather than the traditional vaccine benefit, since it is a monoclonal antibody, but it is included in CDC recommendations and generally covered when indicated. Families should check with their insurer or pediatric office if they have questions about costs.

What remains uncertain

Researchers continue to monitor:

How long protection lasts across multiple seasons.
How RSV virus strains may shift over time.
Whether broad immunization changes overall community transmission patterns.

So far, safety monitoring systems, including FDA MedWatch and CDC surveillance, have not identified unexpected safety concerns beyond those described in clinical trials. Ongoing monitoring remains essential.

What this means for families

For the 2025–2026 RSV season, most U.S. babies can start life with meaningful protection against one of the most common causes of infant hospitalization.

If you are pregnant, ask your obstetric clinician whether maternal RSV vaccination is recommended for your due date and region. If you have a newborn or young infant, ask your pediatrician whether your baby is already protected through maternal vaccination or should receive nirsevimab.

RSV has not disappeared—but prevention has improved. For many families, that means fewer severe infections, fewer hospital stays, and a safer first winter.

Sources

This article is for general informational purposes only and is not medical advice. Research findings can be early, limited, or subject to change as new evidence emerges. For personal guidance, diagnosis, or treatment, consult a licensed clinician. For current outbreak or public health guidance, follow your local health department, the CDC, or another relevant public health authority.